@article{ITA_1992__26_5_403_0,
     author = {Steffen, B. and Barry Jay, C. and Mendler, M.},
     title = {Compositional characterization of observable program properties},
     journal = {RAIRO - Theoretical Informatics and Applications - Informatique Th\'eorique et Applications},
     pages = {403--424},
     publisher = {EDP-Sciences},
     volume = {26},
     number = {5},
     year = {1992},
     mrnumber = {1187510},
     zbl = {0768.68088},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1992__26_5_403_0/}
}